According to the NFPA 13, §188.8.131.52.1, sprinklers only need to be installed in obstructions that exceed fixed 4' wide obstructions. The Zenbooth Solo is intentionally designed to be less than 4' x 4' wide so that it does not trigger this requirement.
The Zenbooth Quad & Zenbooth Duo are larger than 4' wide. If a sprinkler is required by a local authority, the booth can be easily modified to include a fire suppression option.
Our customers would typically only purchase this option if required by their building or local authorities. This will vary depending on the building and city. This option can be purchased after your initial purchase & installation if you later find out it's required by local inspectors.